With development of mobile communications systems, user services have raised increasingly high requirements for transmission rates. To ensure a transmission rate of a common user without increasing configured bandwidth and to provide a higher throughput to the user, a carrier aggregation (Carrier Aggregation, CA for short) technology is introduced in the 3rd Generation Partnership Project (The 3rd Generation Partnership Project, 3GPP for short). Carrier aggregation refers to that user equipment (User Equipment, UE for short) can simultaneously use multiple component carriers (Component Carrier, CC for short) to perform uplink and downlink communication, so that high-speed data transmission is supported.
According to types of aggregated carriers, there are two categories: carrier aggregation in a same system and carrier aggregation in different systems. The carrier aggregation in a same system refers to that all carriers used by UE are carriers in a same system. For example, all carriers belong to a Long Term Evolution (Long Term Evolution, LTE for short) system, or all carriers belong to a Universal Mobile Telecommunications System (Universal Mobile Telecommunications System, UMTS for short). The carrier aggregation in different systems refers to that carriers used by UE belong to different systems. For example, carriers belong to an LTE system and a UMTS system, an LTE system and a wireless local area network (Wireless Local Access Network, WLAN for short) system, or a UMTS system and a WLAN system. The carrier aggregation in different systems may fully take advantage of characteristics of various communications systems, to achieve transmission effects of high efficiency and low costs.
In the prior art, when carrier aggregation in different systems that include a WLAN is used to perform data splitting, a data service interruption may occur, which affects a transmission rate.